Teletypewriter



oct. 19, 1937. B s, sw Y 2,096,145

TELETYPEWRITER Filed May 29, 1936 INVENTOR By B.$.SWEZ'V ATTORNEYPatented Oct. 19, 1937 TELETYPEWRITEB Burdette Stevens Swezey, FloralPark, N. Y., as-

signor to American Telephone & Telegraph Company, a corporation of NewYork Application May 29, 1936, Serial No. 82,639

11 Claims.

This invention relates to a motor control device for teletypewritersand, more particularly, to a device for stopping the motor of anunattended teletypewriter which may, if desired, be located at a remotestation.

Heretofore, an operator at a control station has stopped the motor of anunattended teletypewriter, such as a teletypewriter located at a remotestation, by transmitting to the unattended teletypewriter a motor stopsignal composed of a preassigned combination of significant currentvariations, such as those corresponding to an upper case H signal. Asystem of this type is shown in Patent 1,566,295 granted December 22,1925 to E. F. Watson. The disclosure of this Watson patent isincorporated herein by reference as a part of this specification.However, it has been found that, under certain conditions, motors ofunattended teletypewriters have been unintentionally stopped by variouscauses, such as the operator at the control station accidentallystriking the stop key or because of disturbances in the line simulatingan upper case H signal.

Accordingly, this invention has for its object the reduction of suchunintentional stopping of remote motors. This is accomplished byinstalling a mechanical latch and associated parts in the teletypewriterto be controlled. This latch prevents the motor stop lever fromoperating in response to the usual motor stop signals. The latch isdesigned to be released, or unlatched, by a lever which is operated inresponse to the reception of a preassigned teletypewriter signal, suchas a blank signal. The release of the latch allows the operation of themotor stop function lever to be effective to stop the teletypewritermotor. .Thus, the motor of the controlled unattended teletypewriter willbe stopped in response to the reception by that teletypewriter of ablank signal immediately followed by an upper case H signal. The latchis restored to its normal, or operated, position by the operation of theuniversal function lever which operates, after the teletypewriter hasbeen started by a motor start signal, in response to the reception bythat teletypewriter of any teletypewriter signal for causing typing orspacing.

The invention will now be explained in detail with reference to thedrawing in which:

Figure 1 indicates schematically a simple teletypewriter system to whichthe invention may be applied;

Fig. 2 illustrates the preferred embodiment of the invention in itsnormal, or unoperated, condition;

Fig. 3 shows this embodiment in its operated position;

Fig. 4 represents a modified form of the invention in its normal, orunoperated, condition;

and i Fig. 5 shows this modification in its operated condition.

For purposes of explanation, the invention is to be understood as beingapplied to a teletypewriter of the type disclosed in Patent 1,904,164granted April 18, 1933 to S. Morten et al., although the invention isnot restricted to this kind of teletypewriter. The disclosure of thisMorton et al. patent is incorporated herein byreference as a part ofthis specification. The drawing shows only those parts of theteletypewriter that are necessary to illustrate the manner in which theinvention is applied to the teletypewriter shown in the Morton et al.patent. Accordingly, the apparatus shown in the drawing corresponds tothat shown in Figs. 27, 28, etc. of the Morton et al. patent.

In the simple teletypewriter system, shown in Fig. 1, if an operator ata. control station A, which may be a central oflice if desired, wishesto transmit a message to the unattended station B, she first connectsthe telegraph line L to her teletypewriter T by any convenient means,such as switch S. The motor M at the unattended station B may be startedby the operator at station A by any of the methods well known in theart, such as the method described in the Morton et al. patent, supra.The operator then transmits the desired message to station B. After themessage has been transmitted to station B, the operator at station A maywish to stop motor M at station 13 in which case she first transmits apreassigned signal over line L to station B. This preassigned signal maybe any desired signal, such as a socalled blank signal in which all thecurrent impulses composing the code signal are spacing impulses.

Just before this blank signal is received, the motor control apparatusat station B is in its normal, or unoperated, condition as is shown inFig. 2 which is somewhat similar to Fig. 27 of the Morton et al. patent,supra, except for a few added parts. One of the parts addedis a. bentlever ll having'one end secured to the pivot 482 o! lever 483 and theother end attached to the end 415 of arm 41.4 of T-lever 4 by theadiusting screw "6. Another added part is a hairpin member l4 clampedbetween the bent lever II and a plate l3 by bolts l2-l2. Still anotheradded art is a blocking lever l5 pivotally attached to the anchor plate8 by a fixedly located pivot I6.

This blocking lever I5 has one'end I1 positioned between the prongs ofmember I4 and has its other end I 8, which is notched, normally inengagement with the motor stop function lever 48L.

Thus, under normal conditions, the motor stop function lever 48I can notbe operated because, as can be seen in Fig. 2, its travel forward'is'blocked by its engagement with the notched end I8 of lever I5. Sincelever I5 is heldin place by pivot I6, which is fixedly located, leverlican not be pushed forward to allow function lever 4lI to rotate forward.

When the blank signal is received, the selecting mechanism of theteletypewriter T1 at station B operates to actuate the "blank functionlever 463 which accordingly moves its extension 465 downward.This'causes arm 4 of T-lever 461 to also move downward thereby rotatingT- lever 461 about its pivot 458 to its operated position where it isheld by'means of the spring washer 412. The rotation of T-lever 461causes its vertical arm "I, which is pivotally connected to arm 413 ofT-lever 444 by pivot496, to force T-lever 444 to the left.

When T-lever 444 moves to the left, it carries with it the lever II,plate I3 and'the hairpin member I4. Themovem'ent of member I4 to theleft, shifts the end I1 of the blocking lever I! to the left therebyswinging the notched end II of lever I5 to the right out of engagementwith function lever 4M which is thus conditioned for operation as isshown inFig. 3. y

The operator at station A now transmits a socalled shift" signal.In'response to the reception of this shift signal, the sixth vane 50 ofthe teletypewriter T1 will move to tilt its front end downward as isdescribed in the Morton et a1. patent. The sixth vane 50 is thus placedin the proper position to allow the motor stop function lever "I to beselected andto move forward to perform its functions.

The operator next transmits the third signal which may be another shiftsignal as' described in the Morton et al. patent, or, more preferably,

a preassigned signal such as I-I" as is described in the Watson patent,supra. The selecting mechanism in the teletypewriter T1 responds. tothis code signal and effects the selection .of the motor stop functionlever 48I which operates and rotates clockwise on its pivot I18 therebymoving its arm 506 downward until the extension 534 contacts with theadjusting screw. 419.

As is described in the Morton et al. patent, supra, the rotation of themotor stop function lever 48I moves its other arm 505 upward therebycausing the arm 509 of the motor stop lever 502 to strike against theend "I of the, contact operating lever499 which, consequently, rotatesclockwise on its pivot I16. In rotating, lever4l9 moves its other end503 downward to allow'contact 491 to open thereby effecting theopeningof the energizing circuit of motor M with the consequent stopping ofmotor M. Itshould be noted that contact 498 will be closed for-a briefinterval by arm 506 to allow the printing cycle to be completed for thepurpose described in the Morton et al. patent, supra, or for performingany other function that may be'desired.

- The energizing circuit of the motor M will now remain open until theoperator at station A transmits a start signal to close contact 481 andstart motor M, such as-in the manner described in the Morton et al.patent, supra. Then, upon the receipt of any code signal which causesprinting or spacing, the universal function lever 490 will operate andmove its arm 4 downward thereby forcing downward arm 4" of T-lever 461and V shifting the vertical arm 4 to the right. This pulls T-lever 444and the bent lever II to the right. As a result, member I4 is moved tothe a right thereby shifting end I1 of lever It to the right and movingthe notched end II to left and into engagement with function lever Ithus restoring the motor stop apparatus to its'normal condition as shownin Fig. 2.

Thus, it can be seen, that by means of this motor stop device, theremotely controlled teletypewriter motor can be stopped only in responseto combinations of three signals: namely, "blank, shift", and "H" orshift, blank", and H". If desired, the device could bedesigned, bymodifying the arrangementof the selecting vanes and their associatedapparatus, to operate with the motor stop signal describedin the Mortonet a1. patent and would then be fblank, "shift", and shift or shift",fblankffi'and "shift". It is to be understood that any other suitablecharacter, such as M", may. be used instead of "H", if desired. In thisconnection it'should be noted that, since the universal function lever400 opcrates only in respons'e toany signal which causes printing orspacing, function combinations, may be interposed in the abovesequencesand will have no detrimental effect on the operation ofwthe signalis-.transmitted,1the apparatus is notin the.

condition to respond'en'ectively to the upper case Hflsignal because,should the motor stop function lever I then attempt to enter theselector vanes of the teietypewriter, it would find its forward movement1 blocked by lever Ii. These motor stop contacts may be employed in avariety of circuits, such as. in place of the stop bar contacts I3 shownin Fig. l. in Patent 2,031,934 granted February 25, i936 to T. L.Corwin. The disclosure of this vCorwin patent is incorporated herein byreference as a part of this specification. It is to'be understoodthatjthese motor'stop contacts may be designed to be normally open andV,

to stop the motor on'being closed.

A modification of the invention is shown in Figs. 4 and 5. In thismodification, a small plate" 3 is attached to the end 415 of arm 414 ofT-lever ve'dly secured to extension 418 by the adjusting screw 41! isanarm S which ten'ds to bepulled upward toward arm I byaretractivecofled spring 4 thereby biasing T-lever 444 so that the plate3 will not rub on the arm I.

Since the adjusting screw 41! is located im'niediately beneath extension534 of arm I ofthe function lever 4III, lever 48I can not 'move forwardat this its extension "4 is" held up aslong as plate I is held up byarm I. I The motor stop function lever 48I is thus 112- strained fromoperating at this time.

With this modification of theinv'ention, when a blank" signal isreceived, the movement of the vertical arm 41! of T-lever 461 movesT-lever 444 to the left as was described above. When T-lever 444 movesto the left, plate 3, which is secured to the end 415 of arm 414, movesto the left a distance sufficient to allow plate 3 to clear the arm i.Plate 3 and arm 414 are now free to move downward below arm I therebyconditioning the device for downward movement of extension 534 and arm506 01 the function lever 48!.

The operator at station A now transmits a so-called shift signal. Inresponse to the reception of this shift signal, the sixth vane 50 of theteletypewriter T1 will move to tilt its front end downward as isdescribed in the Morton et al. patent. The sixth vane 50 is thus placedin the proper position for allowing the motor stop function lever "I tomove forward to its operated position.

The operator next transmits the third code signal which may be another"shift signal as described in the Morton et a1. patent, or, morepreferably, a preassigned signal such as H as described in the Watsonpatent supra. The selecting mechanism in the teletypewriter Tl respondsto this code signal and effects the selection of the motor stop functionlever 48l which operates and rotates clockwise on its pivot I16 therebymoving arm 506 downward and carrying with it the extension 534 and theadjusting screw 419 on extension 418 of arm 4'" as is shown in Fig. 5.

As is described in the Morton et a1. patent, the operation of the motorstop function lever 48l moves its other arm 505 upward thereby causingthe extension 509 to strike against the end 50I of the contact operatinglever 499 which, consequently, rotates clockwise on its pivot I16. Inrotating, lever 499 moves its other end 503 downward to allow contact491 to open thereby effecting the opening of the energizing circuit ofmotor M with the consequent stopping of motor M. The energizing circuitof the motor M will now remain open until the operator at station Atransmits a start signal to close contact 491 and start motor M, such asin the manner described in the Morton et a1. patent, supra. Then, whenthe universal function bar 490 operates as described above, T- lever 444will be pulled to the right thereby moving plate 3 to the right also.Since spring 4 tends to pull T-lever 444 upward against the stop screw2, plate 3 will now be restored to its normal position immediatelyoverhanging arm I as shown in Fig. 4.

As was stated above, the invention is not limited to the use of "blankand upper case H signals, but may be adapted to operate in response toany other combinations of teletypewriter signals. It is also to beunderstood that the invention is readily applicable to attendedteletypewriters. Various other modifications may be made in theinvention which is to be limited only by the claims appended hereto.

What is claimed is:

1. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second station.

for operating the teletypewriter thereat, a circuit for energizing themotor, a control contact connected in series with the energizing circuitfor opening and closing said circuit, motor starting means for closingthe control contact, motor stopping means for opening the controlcontact, said motor stopping means comprising a lever for efiecting theopening of the control contact, a

latch for preventing the lever from effecting the opening of the controlcontact, and an instrumentality responsive to the reception by theteletypewriter at the second station of a preassigned permutation codesignal for unlatching the latch for permitting operation of the lever.

2. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations. a motor at the second station for operatingthe teletypewriter thereat, a circuit for energizing the motor, acontrol contact connected in series with the energizing circuit foropening and closing said circuit, motor starting means for closing thecontrol contact, motor stopping means for opening the control contact,and operating means for operating the -motor stopping means, saidoperating means being responsive to the reception by the teletypewriterat the second station of three different successive permutation codesignals transmitted over the telegraph line by the teletypewriter at thefirst station.

3. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second sta tion foroperating the teletypewriter thereat, a

circuit for energizing the motor, a control contact connected in serieswith the energizing circuit for opening and closing said circuit, motorstarting means for closing the control contact, motor stopping means foropening the control contact, said motor stopping means comprising alever for effecting the opening of the control contact, a latch forpreventing the lever from efiecting the opening of the control contact.an instrumentality responsive to the reception by the teletypewriter atthe second station of a preassigned permutation code signal forunlatching the latch for permitting operation of the lever, and meansfor restoring the latch to its latched position.

4. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line for connectting the two stations. a motor at thesecond station for operating theteletypewriter thereat, a circuit for energizing the motor, a controlcontact connected in series with the energizing circuit for opening andclosing said circuit, motor starting means for closing the controlcontact, motor stopping means for opening the control contact, saidmotor stopping means comprising a lever for effecting the opening of thecontrol contact, a latch for preventing the lever from eflfecting theopening of the control contact, an instrumentality responsive to thereception by the teletypewriter at the second station of a preassignedpermutation code signal for unlatching the latch for permittingoperation of the lever, and means responsive to certain preassignedpermutation code signals for restoring the latch to its latchedposition.

5. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second station for operatingthe teletypewriter thereat, a circuit for energizing the motor, acontrol contact connected in series with the energizing circuit foropening and closing said circuit, motor starting means for closing thecontrol contact, a motor stop function lever for eifecting the openingof the control contact, and a blocking leverfor preventing the motorstop function lever from efiecting the opening of the control contact.

6. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second station for operatingthe teletypewriter thereat, a circuit for energizing the motor, acontrolcontact connected in series with the energizing circuit for opening andclosing said circuit, motor starting means for closing the controlcontact, a motor stop function lever for effecting the opening of thecontrol contact, a pivoted blocking lever for preventing the motor stopfunction lever from efiecting-the opening of the control contact, andmeans for swinging the blocking lever about its pivot to release themotor stop i'unctionlever ,for operation.

7. A teletypewriter system having in combination a first teletypewriterstation, a second tele typewriter station, a telegraph line forconnecting thetwo stations, -a motor at the second station for.operating the teletypewriter thereat, a circuit for energizing themotor, a control contact connected inseries with the energizing circuitfor opening and closing said circuit, motor starting means for closingthe control contact, a motor, stop function lever for eflecting theopeningof the control contact, a pivoted blocking lever for preventingthe motor stop function lever from effecting theopening of the controlcontact, and means responsive to the reception by the teletypewriter atthe second station of a.

preassig'ned permutation code signal for swinging the blocking leveraround its pivot to release the motor stop function lever for operation.

8. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second station for operatingthe teletypewriter'thereat, a circuit for energizing the motor, acontrol contact connected in series with the energizing circuit foropening and closing said circuit, motor starting means for closing thecontrol contact, a motor stop function lever for effecting the owning ofthe control contact, a two-position lever having an operated positionfor preventing operation of the motor stop function lever, a catch forholding the lever in its operated position, and means for releasing thecatch.

9. A teletypewriter system having in combination a first teletypewriterstation, a second teletypewriter station, a telegraph line forconnecting the two stations, a motor at the second stacatch for holdingthe lever in its operated position, means for releasing the catch, andmeans responsive to the reception by the teletypewriter at the secondstation of a preassigned teletypewriter signal i'or releasing the catch.

' 10. A teletypewriter system having in combination a firstteletypewriter station, a second teletypewriter station, a telegraphline for connecting the two stations, a motor at the second station foroperating the teletypewriter thereat, a circuit for energizing themotor, a control contact connected in series with the energizing circuitfor opening and closing said circuit, motor starting means for closingthe control contact,

a motor stop function lever for eilecting the opening of the controlcontact, a two-position lever having an operatedposition for preventingoperation of the motor stoprfunction lever, a catch for holding thelever in its operated position, means for releasing the catch, andrestoring means for restoring the catch for placing the two-positionlever in its operated position.

I 11. A teletypewriter system having in combination a firstteletypewriter station, a second teletypewriter station, a telegraphline {for connecting the two stations, a motor at the second station foroperating the teletypewriter thereat, a circuit for energizing themotor, a control contact connected in series with the energizing circuitfor opening and closing said circuit, motor startingmeans for closingthe control contact, a motor stop function lever for effecting theopening of the control contact, a two-position lever having an operatedposition for preventing operation of the motor stop function lever, acatch for holding the lever in its operated position, means forreleasing the catch, means responsive to the reception by theteletypewriter BURDE'I'IE STEVENS SWEZEY.

